There are a number of conventional processes for packaging integrated circuit (IC) dice. By way of example, many IC packages utilize a metallic leadframe that has been stamped or etched from a metal sheet to provide electrical interconnects to external devices. The die may be electrically connected to the leadframe by means of bonding wires, solder bumps or other suitable electrical connections. In general, the die and portions of the leadframe are encapsulated with a molding material to protect the delicate electrical components on the active side of the die while leaving selected portions of the leadframe exposed to facilitate electrical connections to external devices.
During testing as well as typical operation, packages may be repeatedly exposed to temperature cycling and other environmental stresses. Stresses tend to concentrate in regions of the package where materials with different coefficients of thermal expansion meet, such as the interface between the die and the surrounding molding material. Such stresses may lead to damage to the electrical connections and damage to the die itself, as well as other problems, and may render the device inoperable or at least adversely affect the performance of the device.
Semiconductor manufacturers have added various features, such as cavities and lids, to certain types of IC packages in order to better protect the integrated circuit dice within the packages. These features, however, may entail higher costs and/or require the use of specialized packaging equipment. Although existing approaches have worked well in certain applications, there are continuing efforts to develop more reliable and efficient methods and apparatuses.